Communication of event messages in computing systems

ABSTRACT

A method and system. A first computer device sends to a second computer device, via a broadcast or multicast communication, an event notification of a notifiable management event. The first computer device may connect to a management network via only a first network switch, wherein the first computer device is unable to notify a management device of the notifiable management event via the management network because the first computer device is unable to connect to the management network via the first network switch. The first computer device receives, from the second computer device via a first unicast communication, an acknowledgment of the event notification, wherein the second computer device is able to connect to the management network via the second network switch. The broadcast or multicast communication and the first unicast communication each use a short-range wireless communications technology comprising visible light communication or data-over-audio communication.

This application is a continuation application claiming priority to Ser.No. 15/231,064, filed Aug. 8, 2016.

TECHNICAL FIELD

The present invention relates to computing systems, and morespecifically, to the management of computing systems.

BACKGROUND

Computing systems comprising computer devices connected by datacommunications networks increasingly are growing in scale to meetconsumer demand. In large-scale computing systems, computer devices andassociated cabling and hardware may be located in large computer roomsand data centers in specially designed storage cabinets or racks thatallow access thereto by operators, such as maintenance staff. Thearrangement of storage cabinets in a computer room may be based on anumber of design considerations. Such considerations include: topologydesign relating to the overall use of space within the room; generalinfrastructure design relating to the arrangement of mechanical systems(e.g., cooling systems) and electrical systems (e.g., power system)within the room, and technology infrastructure design relating to thearrangement of the computer systems hardware, communications networkcabling etc., within the room.

Typically, computer rooms arrange storage cabinets in rows, in whichpairs of rows of storage cabinets are arranged with their fronts facingopposite each other with an aisle in between, to allow for access bymaintenance staff, as shown in FIG. 1A which is a schematic diagram ofan arrangement of part of a computing system in a computer room showingan example technology infrastructure design. One such design conceptthat may be used in data centers is the so-called “hot aisle/cold aislelayout”, which comprises rows of storage cabinets spaced by alternate“hot aisles” and “cold aisles”, as shown in FIG. 1B which is schematicdiagram of an arrangement of part of a computing system in a computerroom showing an example general infrastructure design. In FIG. 1B, thefronts of rows of cabinets face into a cold aisle and the backs of rowsof cabinets face into a hot aisle. A cooling system is arranged tocontrol the flow of air around the cabinets for heat dissipation, so asto prevent overheating. In particular, the cooling system may bearranged to provide cold air into the fronts of the cabinets, and thusin front of the computing devices in the cabinets, via the “coldaisles”. For example, as shown in FIG. 1B, cold air may flow from thefloor of the cold aisles and into the fronts of the adjacent rows ofcabinets as shown by arrows shaded as “cold air”. The cooling system isfurther arranged to extract hot air, which is vented, for example byfans in the computing devices, from the backs of the rows of cabinetsvia the “hot aisles”. For example, as shown in FIG. 1B, hot air may flowin a direction towards one end of the rows as shown by arrows shaded as“hot air”.

In practice, when storage cabinets for computer devices are arranged inrows, the computer devices in each row of cabinets are connected to thesame communications cabling, and thus part of the same system network.However, it is not usually possible to provide cabling between adjacentrows of cabinets, for practical reasons and/or design considerations,and so computer devices in adjacent rows of cabinets are typicallyconnected to different network segments of the system network.

Computer systems require continuing management for maintenance and toremedy faults giving rise to operational and/or performance errors. Forthis purpose, individual computer devices, such as servers, may include“diagnostic tools”, typically comprising automated diagnosticmonitoring, which may identify errors or events based on diagnosticinformation. An identified error or event may be indicated to anoperator, for example by means of a display on the front panel of thecomputer device. For instance, a particular light, such as an indicatorLED, on the front panel of the computer device may be lit in particularmanner to indicate a certain type of error.

In addition, more advanced diagnostic tools may report identified errorsin computer devices as “events” to a local or remote managementapparatus or console, by sending management data, for example as an“event message” including associated error and diagnostic information,over a management network. In particular, a so-called Advanced SystemManagement module (also known as System Management Interface) may beprovided in each computer device (e.g., server) for diagnosticmonitoring and reporting using proprietary communications and messagingformats. Such advanced diagnostic monitoring enables a fault or otherproblem to be identified by an operator of a management device orconsole at a remote location, and, in some cases, may allow for thefault or problem to be fixed or otherwise resolved remotely. In order toprovide such advanced diagnostic functionality, each computer deviceneeds to be able to connect to a management network for reporting eventsto the management console. However, if a fault exists in the connectionof a computer device to the system network, the computer device isunable to connect to the management network via the system network. Inorder to address this issue, conventional network configurations providea second system network to provide redundancy (hereinafter called“redundant network”), as shown in FIG. 2A and described below. In thisway, if a computer device is unable to connect to the system network,the computer device is able to report the fault as an event over theredundant network to the management console.

FIG. 2A shows a conventional network configuration for a part of thecomputing system of FIGS. 1A and 1B. FIG. 2A comprises computer devicesof a first row 12, computer devices of a second row 14, and aisle 16between the first row 12 and the second row 14, where the computerdevices are depicted as servers. Each server of the first row 12 isconnected to a first network switch X for the network segment of thesystem network (shown in solid line in FIG. 2A). In addition, eachserver of the first row 12 is connected to a second network switch Y,providing a redundant network (shown in dashed line in FIG. 2A).Similarly, each server of the second row 14 is connected tocorresponding first and second network switches X and Y associated withthe system network and the redundant network, respectively. Thus, asshown in FIG. 2A, the provision of a redundant network requires anadditional network switch Y for each segment and additional cabling toeach computer device, which may clutter the storage cabinets in eachrow, increase energy consumption and reduce heat dissipation, as well asincrease infrastructure costs. In FIG. 2A, the first and second networkswitches X and Y are connected to a management console 70 via a systemnetwork 65.

SUMMARY

The present invention provides a method and associated system andcomputer program product. A first computer device identifies anotifiable management event relating to the first computer device,wherein the first computer device is unable to notify a managementdevice of the notifiable management event via a management networkbecause the first computer device is unable to connect to the managementnetwork. The first computer device sends, to a second computer devicevia a broadcast or multicast communication, an event notification of thenotifiable management event. The first computer device receives, fromthe second computer device via a first unicast communication, anacknowledgement of the event notification, wherein the second computerdevice is able to connect to the management network. The broadcast ormulticast communication and the first unicast communication each use ashort-range wireless communications technology.

BRIEF DESCRIPTION OF THE DRAWINGS

Example implementations of the present invention will be described belowwith reference to the following drawings.

FIG. 1A is a schematic diagram of an arrangement of part of a computingsystem in a computer room showing an example technology infrastructuredesign.

FIG. 1B is schematic diagram of an arrangement of part of a computingsystem in a computer room showing an example general infrastructuredesign.

FIG. 2A is a schematic block diagram showing a conventional networkconfiguration for a part of the computing system of FIGS. 1A and 1B.

FIG. 2B shows a network configuration for a part of the computing systemof FIGS. 1A and 1B, in accordance with embodiments of the presentinvention.

FIG. 3 is a block diagram of a system, in accordance with embodiments ofthe present invention.

FIG. 4 is a flowchart illustrating a method for communicating managementdata, in accordance with embodiments of the present invention.

FIG. 5 is a flowchart illustrating a method for communicating managementdata, in accordance with embodiments of the present invention.

FIG. 6 is a flowchart illustrating a method for facilitatingbidirectional communication of management data, in accordance withembodiments of the present invention.

FIG. 7 is schematic diagram of an arrangement of part of a computingsystem in a computer room, in accordance with embodiments of the presentinvention.

DETAILED DESCRIPTION

Example implementations of the present invention include systems,methods and computer program products for communicating management data,such as the above-described event messages, over a management network toand from a computer device, wherein the computer device is not able toconnect to the management network, for example due to a fault in anetwork connection. The disclosed example implementations may be usedfor managing computer devices (e.g., servers) in computing systems, forexample housed in computing rooms and data centers comprising rows ofstorage cabinets, in order to reduce, or even eliminate, the need toprovide a redundant network. In the drawings, the same or similarfeatures are assigned the same or similar reference numerals.

FIG. 3 is a block diagram of a system 1, in accordance with embodimentsof the present invention. The system 1 comprises a plurality of computerdevices 10, such as servers, only one of which is shown for ease ofillustration. As the skilled person will appreciate, computer device 10may comprise any other type of device in a computing system capable ofdiagnostic monitoring. In the example implementation of FIG. 3, computerdevice 10 comprises a memory unit 20 in communication with a processingunit 30 which represents one or more processors. Memory unit 20comprises memory, which represents one or more memory units, for storingdata for processing by processing unit 30, including processing modules22 comprising program code for execution by processing unit 30. Inparticular, in accordance with example implementations of the presentinvention, memory unit 20 stores an Advanced System Management (ASM)module 24 for monitoring the computing device 10 and obtainingdiagnostic information for identifying errors in the operation and/orperformance of the computing device 10. As the skilled person willappreciate, the ASM module 24 may comprise any suitable diagnostic toolfor collecting management data and identifying errors, which mayindicate faults, in the computing device 10, or any associated deviceconnected thereto (not shown). As indicated above, such diagnostictools, and the processing used to provide the associated diagnosticfunctions, are well known to the skilled person and so are not describedin detail in the present invention. Examples of such diagnostic toolsfor management of computing systems include: Integrated ManagementModule (IMM) of IBM Corporation, and Integrated Lights Out (iLO)management interface of Hewlett Packard Enterprise Company.

Computer device 10 further comprises an input/output (I/O) unit 40 and afront-panel unit 50 for communicating data and/or information bycomputer device 10. In particular, I/O unit 40 may be any suitablecommunications interface for enabling communication of data by computerdevice 10 to and from external devices connected thereto. Such externaldevices include, for example, user interface devices 60 connected viaperipheral connections such as USB or Bluetooth connections, and othercomputer devices 10 of the computing system connected via wired orwireless connections to the system network 65. In addition, suchexternal devices may include other local or remote devices connected viawired or wireless connections to one or more other networks such as aLocal Area Network (LAN), a Wide Area Network (WAN) or the Internet, towhich computer device 10 is able to connect via the system network 65.An example of such an external device is a management console 70, asdiscussed in further detail below.

When computer device 10 is able to connect to management console 70 viasystem network 65, ASM module 24 may send management data, such as eventmessages and/or diagnostic information, via I/O unit 40 over systemnetwork 65 to the management console 70. In addition, ASM module 24 mayreceive messages from the management console 70, such as requests fordiagnostic information or instructions for managing errors (e.g., fixingfaults) Diagnostic management processes for such communications betweenASM module 24 and management console 70 over network 65, including the(typically proprietary) message formats and communication protocolsused, are well known to the skilled person and so are not described indetail in the present invention.

Front-panel unit 50 comprises a Light Emitting Diode (LED) unit 52including one or more LED indicator lights. For example, LED unit 52 maycomprise a plurality of indicator LEDs, which may be illuminated to emitvisible light of one or more colors to provide information relating tothe computer device 10. For example, a power indicator LED may be lit toemit green light when power is supplied to computer device 10 (i.e., thedevice is switched on). In addition, ASM module 24 may control one ormore of indicator LEDs to emit light of one or more colors to indicateinformation relating to an operational status of the computer device 10,such as to indicate an error or fault, and, optionally, the severity ofthe error or fault, that has been identified by ASM module 24.

In accordance with example implementations of the present invention,computer device 10 comprises a wireless communications module 80. In theexample shown in FIG. 3, wireless communications module comprises avisible light communications (VLC) module for one-to-many and one-to-onedata communication using visible light as a communications medium. Asthe skilled person will appreciate, in other example implementations,module 80 may implement other types of wireless communications capableof one-to-many and one-to-one data communication, as described furtherbelow. In the example implementation shown in FIG. 3, VLC module 80 maybe implemented as part of the ASM module 24. As the skilled person willappreciate, VLC module 80 may be implemented as an independentprocessing module or otherwise, according to design requirements. VLCmodule 80 enables data to be transmitted from one or more of theindicator LEDs, or a dedicated LED, of the LED unit 52 by visible lightcommunication, such as so-called “Light Fidelity” or “LiFi” inaccordance with IEEE 802.15.7-201—IEEE Standard for Local andMetropolitan Area Networks—Part 15.7 entitled: “Short-Range WirelessOptical Communication Using Visible Light”. IEEE 802.15.7-2011 defines aPHY and a MAC layer for short-range optical wireless communicationsusing visible light, from 380 nm to 780 nm in wavelength, in opticallytransparent media. Thus, VLC module 80 may include a VLC transmitter(VLC Tx) 82 for controlling an LED of LED unit 52 to emit light inaccordance with a VLC-based PHY modulation scheme. Examples of suchmodulation schemes include on-off keying (OOK), variable pulse widthmodulation (VPPM) and color shift keying (CSK) as disclosed in IEEE802.15.7-2011. As the skilled person will appreciate, some or all of thefunctionality of VLC transmitter (VLC Tx) 82 may be included with theLED unit 52.

In addition, in accordance with example implementations of the presentinvention, computer device 10 comprises a wireless communicationsreceiver 84. In the example shown on FIG. 3, the wireless communicationreceiver comprises a VLC receiver (VLC Rx) 84. VLC receiver 84 comprisesa light detecting device, such as a camera, for receiving VLCcommunications. VLC receiver 84 may also comprise processingfunctionality to process received VLC communications or suchfunctionality may be provided in VLC module 80. VLC receiver 84 may beincluded in the front panel unit 50 with LED unit 52, for example as anintegrated device, or fitted as a separate device, for example byinsertion into a USB port in the front panel of the computer device 10.Data received by VLC receiver 90 may be passed via an internal bus toVLC module 80, thereby enabling bidirectional visible lightcommunication.

In accordance with example implementations of the present invention,when computer device 10 is unable to connect to system network 65, ASMcontrol module 24 nevertheless may send management data, such as eventmessages and/or diagnostic information, to a management console 70. Inparticular, in the example implementation of FIG. 3, management data maybe sent, by visible light communication, using VLC module 80, VLCtransmitter 82 and LED unit 53, to a proxy computer device 10′ (e.g.,server 10′ shown in FIG. 2B) that is able to connect to the systemnetwork 65, and thus to the management console 70. In addition, ASMcontrol module 24 may receive messages from the management console 70,such as requests for diagnostic information or instructions for managingerrors (e.g., fixing faults), by visible light communication, using VLCreceiver 90 and VLC module 80 from the proxy computer device 10′.Example implementations of methods for communicating management data bywireless communication, such as visible light communication, inaccordance with the present invention, which may be performed by a firstcomputer device 10 that is unable to connect to a system network 65 anda second, proxy computer device 10′ that is able to connect to thesystem network 65 are described below with reference to FIGS. 4, 5 and6.

In example implementations of the present invention, a computer programproduct 90 may be provided, as shown in FIG. 3. The computer programproduct 90 may include computer readable media 92 having storage media94, which may include one or more hardware storage devices in oneembodiment, and program instructions 96 (i.e., program code)stored onthe storage media 94. The program instructions 96 may be loaded onto amemory unit 20 of computing device 10, for example as theabove-described ASM module 24 and/or VLC module 80, which may includemodules associated with the VLC transmitter 82 and VLC receiver 84. Theprogram instructions 96 may be executable by the processing unit 30 ofthe computing device 10 to perform processing as described below withreference to FIGS. 4, 5 and 6.

FIG. 4 is a flowchart illustrating a method 400 for communicatingmanagement data, embodiments of the present invention. The method 400uses wireless communication, in particular visible light communication.In particular, although n exclusively, the method 400 may be performedby the ASM module 24 in conjunction with the VLC module 80, VLCtransmitter 82 and VLC receiver 84 of a computer device 10, as shown inFIG. 3, when the computer device 10 is not able to connect to a systemnetwork 65, and thus is unable to communicate management data to amanagement console 70.

The method 400 starts at step 405, At step 410, the method optionallymonitors for an error or event that is notifiable to an operator, forexample an operator of remote management console 70. As described abovewith reference to FIG. 3, computer device 10 may include a diagnostictool that performs advanced diagnostic monitoring, for example using ASMmodule 24, in accordance with known techniques. Such diagnostic tools,and associated diagnostic monitoring techniques, may maintain an errorlog of identified errors or and define certain types of errors thatshould be notified as events to an operator. Thus, step 410 may involveperiodically scanning an error log for errors that are notifiable.However, other techniques for monitoring for notifiable events arepossible and contemplated by the present invention.

At step 420, the method determines whether a notifiable error or eventhas been identified. If no notifiable error is identified, the methodreturns to step 410. If a notifiable error is identified, the methodcontinues with step 430 which determines whether a network connection toa management console is available. As described above, errors and faultsmay be reported by diagnostic tools in a computer device of a computingsystem to a remote management console over a system network. However, ifa fault arises, a computer device may be unable to connect to the systemnetwork, and thus unable to report the fault to a management console viathe system network. If step 430 determines that a network connection isavailable, for example because the error does not compromise theconnection or there is a redundant network connection, the methodproceeds to step 440 by transmitting an error notification message viathe network, in accordance with conventional techniques. The method thenends at step 495. However, if step 430 determines that a networkconnection is not available, for example because the error hascompromised the connection to the system network, the method proceeds tostep 450. At step 450 the method transmits an error notification byvisible light communication, such as LiFi, as a “VLC event message”. Forexample, VLC transmitter 82 of VLC module 80 of the computer device 10of FIG. 3 may control an indicator LED, of LED unit 52, to emit light soas to communicate data, comprising the VLC event message, for example inaccordance with the IEEE 802.15.7-2011 standard.

As described above, computer rooms typically store computer devices instorage cabinets arranged in rows, in which pairs of rows of storagecabinets are arranged with their fronts facing into an aisle, as shownin FIG. 1. Thus, a front panel of a first computer device 10 in astorage cabinet in a first row faces front panels of second computerdevices 10′ in an opposite storage cabinet in a second, adjacent rowacross an open aisle (i.e., an optically transparent region).

In example implementations of the present invention, in step 450, firstcomputer device 10 may broadcast the VLC event message and one or moresecond computer devices 10′ opposite the first computer device 10, whichare located in an optical path of the visible light carrying the VLCevent message, may receive the VLC event message by means of respectiveVLC receivers 84. In this case, if more than one second computer device10′ receives the VLC event message, a method for one of the secondcomputer devices 10′ to take ownership of the data communication, andthus handle the VLC event message, is desirable, in order to avoidduplication of data handling. Examples of such techniques are describedbelow with reference to FIG. 5. In further example implementations, theoptical path of the visible light emitted from each first computerdevice 10 may be controlled, so that the visible light carrying thebroadcast VLC event message is incident on only one or a few selectedopposite second computer devices 10′. For example, a shield, lens orother optical device may be provided with the LED of each first computerdevice 10, to control the dispersion of the visible light carrying theVLC event message emitted by the LED so that the visible light isincident on only selected VLC receivers of second computer devices 10′.As the skilled person will appreciate, such a light control device maybe provided with the VLC receivers 84 of the second computer devices10′. In yet further example implementations, only selected secondcomputer devices 10′ are configured to receive or handle broadcast VLCevent messages. Various combinations of the abovementioned techniquesfor handling a broadcast VLC event message are possible and contemplatedby the present invention. In other example implementations of thepresent invention, in step 450, first computer device 10 may transmitthe VLC event message to one or more target second computer devices 10′by multicast communication. In particular, the VLC event message mayinclude an identifier (e.g., serial number or code) of each of thetarget second computer devices 10′ as the destination devices. In any ofthe above cases, the second computer device 10′ handling the VLC eventmessage may send a unicast acknowledgement of the VLC event message byvisible light communication, as described in more detail below.

At step 460, the method determines whether an acknowledgement of the VLCevent message has been received within an acknowledgment time interval(e.g., about 1 second). If step 460 determines that an acknowledgementof the VLC event message has not been received, the method returns tostep 450 and repeats the transmission of the VLC event message, eitherimmediately or after waiting a further time period. Such retransmissionmay be necessary, for example, in the case of a temporary obstruction ofthe aisle. If step 460 determines that that an acknowledgement of theVLC event message has been received, the method proceeds to step 470.

At step 470, the method records the acknowledgement of the VLC eventmessage by marking the error, corresponding to the event, in the errorlog to indicate that the error has been read. As the skilled person willappreciate, other techniques for recording that the VLC event messagehas been acknowledged are possible, and, typically, the technique isselected based on the diagnostic tool, and thus the advanced diagnosticmonitoring technique, used. After step 470, the method may end orproceed to step 480 in order to monitor whether the error has beenremedied.

In particular, at optional step 480, the method waits for apredetermined time interval, for example during which actions may betaken by the operator to remedy the error associated with the event, forexample by fixing an underlying fault. At step 490, the methoddetermines whether the notified error or event has been remedied byactions of the operator or otherwise. For example, step 490 may scan theabove-mentioned error log to see whether the status of the error hasbeen reset, e.g., to “normal”, or otherwise changed to indicate that theerror has been remedied. Other techniques for determining whether thenotified error or event has been remedied are possible, and, typically,any technique is selected based on the diagnostic tool, and thus, theadvanced diagnostic monitoring technique, used.

If step 490 determines that the notified error or event has beenremedied, the method ends at step 495. If, however, the step 490determines that the notified error or event has not been remedied, themethod may return to step 450 and repeats the process of steps 450 to490 by resending the VLC event message.

As the skilled person will appreciate, various modifications may be madeto the method of FIG. 4. For example, the monitoring steps 410 and 420may be performed by another method (e.g., in a separate processingmodule 22). Thus, the method may start at step 430 by receiving, fromanother method, an indication that a notifiable event has beenidentified. Moreover, step 430 also may be performed by another method(e.g., in the same separate processing module), in which case the methodmay start step 450 by receiving, from another method, an indication thata notifiable error has been identified that cannot be sent via thesystem network in accordance with conventional techniques. In addition,while FIG. 4 has been described in relation to notifiable eventsrelating to errors, other types of notifiable events are possible andcontemplated. For example, a notifiable event may require the reportingof diagnostic management data at predetermined time intervals.

As the skilled person will appreciate, the method of FIG. 4 enables afirst computer device 10 of a computing system that is unable to connectto a system network 65 to nevertheless send event messages to amanagement device or console 70 using a second computer device 10′ thatis able to connect to the system network. The second computer device 10′may then act as an intermediary or proxy for the first computer device10, for example using the method of FIG. 5 described below. In this way,an operator of the management console 70 may be alerted to a problemassociated with the event message. The operator may be able to use theevent message to identify the first computer device, including itslocation, and dispatch on-site maintenance staff to manually remedy theproblem. Moreover, in example implementations of the present invention,the operator of the management console 70 additionally may be able toattempt to remedy a problem associated with the event message remotely,over the management network 65, using a second computer device 10′ as anintermediary or proxy, for example as described below with reference toFIG. 5.

FIG. 5 is a flowchart illustrating a method 500 communicating managementdata, in accordance with embodiments of the present invention. Themethod 500 uses wireless communication, in particular visible lightcommunication. In particular, although not exclusively, the illustratedmethod may be performed by the ASM module 24 in conjunction with the VLCmodule 80, VLC receiver 84 and VLC transmitter 82 of a computer device10 as shown in FIG. 3 when the computer device 10 is able to connect toa system network 65 and thus is able to communicate management data to amanagement console 70. In particular, the method may be performed by asecond computer device 10′, as described above, in response to receivinga VLC event message from an opposite first computer device 10 that isnot able to connect to system network 65, for example using the methoddescribed above with reference to FIG. 4. In accordance with theillustrated method, the second computer device 10′ effectively acts as aproxy for communications between the first computer device 10 and amanagement device or console 70 connected to the system network 65(i.e., communications over a management network). Accordingly, for easeof understanding, second computer device 10′ is also referred to hereinas “proxy computer device”, and first computer device 10 is alsoreferred to herein as “originating computer device”.

The method 500 starts at step 505. At step 510, the method detects anerror notification, for example in the form of a VLC event message,received by visible light communication. For example, a VLC receiver 84of second computer device 10′ may receive data comprising a VLC eventmessage, as described above, from a first computer device 10 and forwardthe data via an internal bus to VLC module 80 for processing.

At optional step 520, the method determines whether the second computerdevice 10′ should handle the VLC event message, and thus act as a proxycomputer device, for example by determining whether ownership criteriaare met. In example implementations of the present invention, the methodmay determine whether to handle the VLC event message based on anidentifier (e.g., serial number or code) of the first computer device 10included in the VLC event message. For example, the VLC module 80 ofeach second computer device 10′ may store a list of identifiers of firstcomputer devices 10, located in an opposite storage cabinet, for whichit is designated to handle VLC event messages, and may take ownership ofVLC event messages originating only from those first computer devices10. In other example implementations, the VLC module 80 of the secondcomputer device 10′ may use a random time period algorithm to determinewhether to take ownership. Thus, for example, each VLC module 80 maywait a random period of time and then check that the VLC event messageremains pending (i.e., has not been cancelled or acknowledged, asdescribed below) before taking ownership. In this way, when a broadcastVLC event message is received by more than one second computer device10′, the VLC module 80 of the second computer device 10′ with theshortest random time period will take ownership, and thus act as proxy.As the skilled person will appreciate, other suitable methods orcriteria for determining whether second computer device 10′ shouldhandle the VLC event message are possible and contemplated by thepresent invention.

In addition, as described above, in cases where second computer devices10′ are configured so that only one or a few second computer devices 10′are able to receive and/or handle VLC event messages from first computerdevices 10 in an opposite storage cabinet, step 520 may automaticallydetermine that the second computer device 10′ should handle the datacommunication, or, alternatively, step 520 may be omitted. In the casethat multiple second computer devices 10′ initially take ownership andhandle a received VLC event message, which may be recognized by themanagement console 70 which may decide which of the second computerdevices 10′ to use for further communication (if required), and notifythe second computer devices 10′, accordingly.

If step 520 determines that the second computer device 10′ should nothandle the VLC event message, the method returns to step 510. However,if step 520 determines that the second computer device 10′ should handlethe VLC event message, the method proceeds to step 530 by acting a proxyand handling the VLC event message. In particular, at step 530 themethod sends an error notification, for example in the form of an eventmessage, corresponding to the VLC event message to a management console70. For example, since proxy computer device 10′ is able to connect tosystem network 65, ASM module 24 may send an event message via I/O unit40 over the system network 65 to the management console 70.

At step 540, the method may send an acknowledgement of the VLC eventmessage to the originating computer device 10 by unicast communicationusing visible light communication. Such an acknowledgement maycorrespond to the acknowledgement received at step 440 of the method ofFIG. 4, described above. In example implementations of the presentinvention, step 540 may be performed before or concurrently with step530. In other example implementations, step 540 may be performed afterthe proxy computer device 10′ receives an acknowledgement of the eventmessage, sent at step 530, from the management console 70. After step540, the method ends at step 545.

As the skilled person will appreciate, the method of FIG. 5 enables asecond computer device 10′ that is able to connect to the system network65 to handle management communications on behalf of a first computerdevice 10 that is not able to connect to the system network, and so notcapable of directly communicating with a management console 70 over thesystem network 65. In examples implementing optional step 520, themethod may further ensure that when multiple second computer devices 10′receive a VLC event message, arbitration is performed to determine whichsecond computer device 10′ should take responsibility or ownership forhandling the VLC event message. In this way, the duplication ofprocessing of the same VLC event message by multiple second computerdevices 10′, and corresponding duplication of data traffic on the systemnetwork 65 and processing by the management console 70, is mitigated.

FIG. 6 is a flowchart illustrating a method 600 for facilitatingbidirectional communication of management data, in accordance withembodiments of the present invention. The method 600 communicatesmanagement data using wireless communication, in particular visiblelight communication. In particular, although not exclusively, theillustrated method may be performed by the ASM module 24 in conjunctionwith the VLC module 80, transmitter 82 and VLC receiver 84 of a computerdevice 10 as shown in FIG. 3, when the computer device 10 is able toconnect to a system network 65 and thus is able to communicatemanagement data to a management console 70, and receives and handles aVLC event message from an opposite computer device 10 that is not ableto connect to system network 65. In particular, the method may beperformed by a proxy second computer device 10′, as described above, inresponse to receiving a VLC event message from an opposite firstcomputer device 10 that is not able to connect to system network 65, forexample using the method described above with reference to FIG. 5.

The method 600 starts at step 605. At step 610, the method receives arequest for a tunnel-through, bidirectional connection to the firstcomputer device 10 that sent the error notification in the form of a VLCevent message, by visible light communication. For example, the requestmay be received from a management console 70 over the management network65, in accordance with proprietary communication and message formats,and may include a request to establish a bidirectional visible lightcommunication connection with the first computer device 10. The requestmay include an identifier for the first computer device 10 and mayfurther include instructions for an ASM module 24 of the first computerdevice 10 to perform processing, for example to remedy or otherwiseaddress an error associated with the notified event.

At step 620 the method establishes a bidirectional connection by visiblelight communication with the originating computer device 10. Forexample, the VLC module 80 may drive an LED of the LED unit 52 of proxycomputer device 10′ to transmit a unicast VLC request messageidentifying the originating computer device 10 and including, forexample, a handshaking request to set-up a bidirectional VLC link, inaccordance with IEEE 802.15.7-2011 standard, such as a bidirectionalLiFi link as discussed above. In response, the VLC receiver 84 of proxycomputer device 10′ may receive a VLC response message from theoriginating computer device 10 including, for example, a handshakingresponse and/or acknowledgement, in order to set-up the bidirectionalVLC link. The bidirectional connection may be established using standardtunneling techniques, for example secure shell tunneling to provide asecure, encrypted tunnel for the exchange of management messages anddata. As the skilled person will appreciate, any suitable message formatand communication protocol may be used for establishing thebidirectional VLC link, which, typically, may depend on the type ofvisible light communication employed for a particular application.

Following establishment of a bidirectional VLC link at step 620, themethod proceeds to step 630 by facilitating communication of managementdata between the management console 70 and the originating computerdevice 10 via the bidirectional VLC link. In particular, the ASM controlmodule 24 of proxy computer device 10′ may receive management requestmessages from management console 70 via system network 65 and pass themon to VLC module 80 for sending from LED unit 52 to originating computerdevice 10 via the VLC link. Similarly, the VLC module 80 of proxycomputer device 10′ may receive management response messages fromoriginating computer device 10 at VLC receiver 84 via the VLC link andpass them on to the ASM module 24 for forwarding to management console70 via system network 65. As the skilled person will appreciate, varioustypes of management messages and data may be communicated in step 630 inaccordance with the (typically proprietary) management processes usedfor diagnostic monitoring and management of the computer system, asimplemented in the ASM module 24 and the management console 70 in aparticular application.

At optional step 640, the method determines whether data communicationbetween the management console 70 and originating computer device 10should be terminated, for example by determining whether a notificationindicating the end of the data communication has been received. Such anotification may be received from the management console 70, theoriginating computer device 10 or both, depending upon the managementprocessing used. In example implementations, the notification mayinclude a message that indicates the end of data communication, such asdenoting the resolution of an error that gave rise to the event. Inother example implementations, the notification may comprise an explicitmessage to terminate communication, and, thus, disconnect the VLC link.If step 640 determines that a notification indicating the end of datacommunication has not been received, the method returns to step 630 anddata communication continues at step 630. However, if step 640determines that a notification indicating the end of data communicationhas been received, the method continues to step 650 by disconnecting theVLC link. The method then ends at step 655. As the skilled person willappreciate, data communication may end without any explicit notificationfrom the management console or originating computer device, and step 640may be omitted. For example, the originating computer device and/or theproxy computer device may cease communication of management data at step630. The VLC link may then be terminated automatically at step 650, andthe method may end at step 655 in response thereto.

As the skilled person will appreciate, the method of FIG. 6 uses asecond computer device 10′ that is able to connect to the system network65 to act as proxy for a first computer device 10 that is notable toconnect to the system network and so not capable of communicating withthe management console 70 over the system network 65. In particular, thesecond computer device 10′ is able to communicate with a managementconsole 70 on the management network via the system network 65 as wellas communicating with first computer devices 10 by visible lightcommunication. Thus, the method enables an operator of the managementconsole 70 to receive event notifications, relating to a first computerdevice 10 that is unable to communicate with the management console 70via the system network 65, transparently, i.e., in the same way as theywould be received if the first computer device 10 were able to connectto the management network. Similarly, the method enables an operator ofthe management console 70 to send instructions to a first computerdevice 10, to assist in remedying any identified problems,transparently, i.e., in the same way as they would be sent if the firstcomputer device 10 were able to connect to the system network.

Accordingly, example implementations of the present invention enablecomputer devices 10 of a computing system to communicate management datato a management device or console 70 when the computer devices 10 areunable to connect to the system network 65, which avoids the need toprovide a second network for redundancy as described above in relationto FIG. 2A. In consequence, the network cabling infrastructure requiredmay be reduced, leading to a reduction in energy consumption, reducedcabling in the storage cabinets and consequential improvements in heatdissipation.

In particular, FIG. 2B shows a network configuration for a part of thecomputing system of FIGS. 1A and 1B, in accordance with embodiments ofthe present invention. As shown in FIG. 2B, computer devices of a firstrow 12 and computer devices of a second row 14 are depicted as servers10. Each server of the first row 12 is connected to a single networkswitch X for the network segment of the system network, and each serverof the second row 14 is connected to single network switch X for thenetwork segment of the system network. In the event that a server 10 inthe first row 14 detects a fault, but is unable to connect to the systemnetwork 65, for example due to a fault with the connection to networkswitch X, an event message may be communicated to a management console70 via a proxy computer device 10′. In particular, the server 10 maybroadcast a VLC event message across an aisle 16 to the opposite servers10 in the second row 14, and a server 10′ in the second row 14 may sendan acknowledgement of the VLC event message to the server 10 by visiblelight communication, for example using the method described above withreference to FIG. 4. As shown in FIG. 2B, a bidirectional VLC link (asshown by the arrow in FIG. 2B) may be established between the server 10in the first row 12 and the server 10′ in the second row 14 to enableserver 10 to communicate with management console 70 via the VLC link andsystem network 65, with the server 10′ as proxy, for example using themethod described above with reference to FIG. 6.

FIG. 7 is a schematic diagram of an arrangement of part of a computingsystem in a computer room, in accordance with embodiments of the presentinvention. The computing system 700, which may correspond to thecomputing system of FIG. 3, comprises first and second rows of storagecabinets 712, 714 positioned opposite each other with their frontsfacing into an aisle 716. For ease of illustration, only two rows ofcabinets 712, 714 are shown. A plurality of first computer devices 710(analogous to computer devices or servers 10 in FIG. 2B) are stored inthe first row of storage cabinets 712. The first computer devices 710may be connected a first segment of system network, for example as inthe network segment of the servers in row 12 of FIG. 2B. A plurality ofsecond computer devices 710′ (analogous to computer devices or servers10′ in FIG. 2B) are stored in the second row of storage cabinets 714.The second computer devices 710′ may be connected to a second segment ofsystem network, independent of the first network segment, for example asin the network segment of the servers in row 14 of FIG. 2B.

In example implementations of the present invention, each of the firstcomputer devices 710 in the first row of storage cabinets 712 and eachof the second computer devices 710′ in the second row of storagecabinets 714 may be configured for visible light communication. Thus,visible light communication may take place between each of the firstcomputer devices 710 and the second computer devices 710′ across theaisle 716, which provides optically transparent media for thecommunication of visible light. In example implementations of thepresent disclosure, first computer devices 710 in the first row ofstorage cabinets 712 and second computer devices in the second row ofstorage cabinets 714 may be configured to send broadcast or unicast datacommunications by visible light communication, and, thus, may beconfigured to perform the method of FIG. 4. In example implementationsof the present invention, one or more of the plurality of secondcomputer devices 710 in the second row of storage cabinets 714 may beselectively configured to receive and/or handle data communications byvisible light communication with a predetermined subset of the pluralityof first computer devices 710 in the first row of storage cabinets 712substantially opposite thereto, and thus may be configured to performthe method of FIG. 5 and/or FIG. 6. In example implementations of thepresent invention, one or more of the plurality of first computerdevices 710 in the first row of storage cabinets 712 may be selectivelyconfigured to receive and/or handle data communications by visible lightcommunication from a predetermined subset of the plurality of secondcomputer devices 710′ in the second row of storage cabinets 714substantially opposite thereto, and thus may be configured to performthe method of FIG. 5 and/or FIG. 6.

As the skilled person will appreciate, various modifications and changesmay be made to the infrastructure design arrangement of the computingsystem of FIG. 7, in accordance with example implementations of thepresent invention. For example, one or more VLC receiver device,independent of the computer devices, may be provided for receiving a VLCevent message. For example, a VLC receiver connected to the systemnetwork may be provided at a location adjacent an aisle between thefronts of storage cabinets, and positioned within optical paths toreceive visible light communications from LEDs of the first and/orsecond computer devices Thus, in example implementations, VLC receiverdevices may be positioned at a location above, below or adjacent theaisle, and visible light from LEDs of the first computer devices may bedirected (e.g., by optical devices as described above and/or mirrors atappropriate infrastructure locations) towards one or more of the VLCreceiver devices. Such receiver devices may include a processing unitconfigured for processing and handling event messages using processessimilar to the method described above in relation to FIG. 5. Inaddition, receiver devices may also be provided with an LED and VLCtransmitter, to enable bidirectional visible light communication asdescribed above in relation of FIGS. 5 and/or 6.

As the skilled person will appreciate, the described exampleimplementations of the present invention provide short range wirelesscommunication using visible light communication. Other types of wirelesscommunication, already known and that may be developed in the future,which are capable of at least one to many communication (i.e.,broadcast/multicast), and preferably also one to one communication(i.e., unicast) are possible and contemplated. For example, alternativeexample implementations may use data over audio communicationtechniques, such as so-called “LISNR technology” developed by LISNR,Inc. of Cincinnati, Ohio. LISNR technology implements a communicationprotocol based on high frequency, inaudible sound signals as described,for example in International Patent Publication No. WO-A-2013/166158.LISNR technology provides for one to many (broadcast/multicast)communication, and may be implemented for bidirectional one to one(unicast) communication by means of a pair of unidirectionalcommunication links. In examples implementing LISNR communicationtechnology, each computer device may include a suitable LISNRtransmitter (e.g., loudspeaker and LISNR communications interface) and asuitable LISNR receiver (e.g., microphone and LISNR communicationsinterface), in place of the VLC module, VLC transmitter and VLC receiverof the example implementations described above. As the skilled personwill appreciate, other suitable types of wireless communication arepossible and contemplated.

Whilst the above description relates to the communication of managementdata, relating to computer devices of a computing system, to and from amanagement console on a management network, the techniques disclosedherein may be used to communicate other types of data that need to besent from other types of device on other separate networks that may beconnected to a system network.

The present invention may be a system, a method, and/or a computerprogram product at any possible technical detail level of integration.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages. The computer readable program instructions may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider). In some embodiments, electronic circuitry including,for example, programmable logic circuitry, field-programmable gatearrays (FPGA), or programmable logic arrays (PLA) may execute thecomputer readable program instructions by utilizing state information ofthe computer readable program instructions to personalize the electroniccircuitry, in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

A computer program product of the present invention comprises one ormore computer readable hardware storage devices having computer readableprogram code stored therein, said program code executable by one or moreprocessors to implement the methods of the present invention.

A computer system of the present invention comprises one or moreprocessors, one or more memories, and one or more computer readablehardware storage devices, said one or more hardware storage devicecontaining program code executable by the one or more processors via theone or more memories to implement the methods of the present invention.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers or ordinary skill in the art to understand the embodimentsdisclosed herein.

What is claimed is:
 1. A method, said method comprising: sending, by afirst computer device to a second computer device via a broadcast ormulticast communication, an event notification of a notifiablemanagement event, wherein the first computer device may connect to amanagement network via only a first network switch, wherein the firstcomputer device is unable to notify a management device of thenotifiable management event via the management network because the firstcomputer device is unable to connect to the management network via thefirst network switch, wherein the first computer device and the secondcomputer device are physically separated by an aisle; receiving, by thefirst computer device from the second computer device via a firstunicast communication, an acknowledgment of the event notification,wherein the second computer device is able to connect to the managementnetwork via the second network switch, wherein the broadcast ormulticast communication and the first unicast communication each use ashort-range wireless communications technology comprising visible lightcommunication or data-over-audio communication.
 2. The method of claim1, wherein a first row of computer devices comprise the first computerdevice, wherein a second row of computer devices comprise the secondcomputer device, and wherein the first row of computer devices and thesecond row of computer devices are physically separated by the aisle. 3.The method of claim 2, wherein each computer device in the first row mayconnect to the management network via only the first network switch. 4.The method of claim 2, wherein the first computer device is opposite thefirst computer device across the aisle.
 5. The method of claim 1, saidmethod further comprising: maintaining, by the first computer device, alog of management events relating to the first computer device, and inresponse to said receiving the acknowledgment of the event notification,recording, by the first computer device, the notifiable management eventin the log of management events.
 6. The method of claim 1, said methodfurther comprising: receiving, by the first computer device from thesecond computer device via a second unicast communication, datacommunications that include a management request from the managementdevice on the management network; processing, by the first computerdevice, the management request to provide a management response, andsending, by the first computer device to the second computer device viaa third unicast communication, the management response for forwarding,by the second computer device, the management response to the managementdevice over the management network, wherein the second unicastcommunications and the third unicast communication use the short-rangewireless communications technology.
 7. The method of claim 1, saidmethod further comprising: receiving, by the second computer device fromthe first computer device via the broadcast or multicast communication,the event notification of the notifiable management event; determining,by the second computer device, that the second computer device shouldhandle the event notification, and in response to said determining thatthe second computer device should handle the event notification,sending, by the second computer device to the first computer device viathe first unicast communication, the acknowledgment of the eventnotification.
 8. The method of claim 7, wherein, prior to said sendingthe acknowledgment of the event notification, the method furthercomprises: sending, by the second computer device to the managementdevice over the management network, the event notification; andreceiving, by the second computer device from the management device overthe management network, the acknowledgment of the event notification. 9.The method of claim 7, said method further comprising: receiving, by thesecond computer device from the management device over the managementnetwork, a management message including a request to establish atunnel-through bidirectional link with the first computer device formanagement data communications; in response to said receiving themanagement request, the second computer device setting up abidirectional unicast communication link with the first computer device,wherein the bidirectional unicast communication uses the short-rangewireless communications technology.
 10. The method of claim 9, saidmethod further comprising: facilitating management data communicationsbetween the management device and the first computer device usingunicast communication over the bidirectional link.
 11. A system,comprising: a first computer device, said system configured to execute amethod, said method comprising: sending, by the first computer device toa second computer device via a broadcast or multicast communication, anevent notification of a notifiable management event, wherein the firstcomputer device may connect to a management network via only a firstnetwork switch, wherein the first computer device is unable to notify amanagement device of the notifiable management event via the managementnetwork because the first computer device is unable to connect to themanagement network via the first network switch, wherein the firstcomputer device and the second computer device are physically separatedby an aisle; receiving, by the first computer device from the secondcomputer device via a first unicast communication, an acknowledgment ofthe event notification, wherein the second computer device is able toconnect to the management network via the second network switch, whereinthe broadcast or multicast communication and the first unicastcommunication each use a short-range wireless communications technologycomprising visible light communication or data-over-audio communication.12. The system of claim 11, wherein a first row of computer devicescomprise the first computer device, wherein a second row of computerdevices comprise the second computer device, and wherein the first rowof computer devices and the second row of computer devices arephysically separated by the aisle.
 13. The system of claim 12, whereineach computer device in the first row may connect to the managementnetwork via only the first network switch.
 14. The system of claim 12,wherein the first computer device is opposite the first computer deviceacross the aisle.
 15. The system of claim 11, said method furthercomprising: maintaining, by the first computer device, a log ofmanagement events relating to the first computer device, and in responseto said receiving the acknowledgment of the event notification,recording, by the first computer device, the notifiable management eventin the log of management events.
 16. A computer program product,comprising one or more computer readable hardware storage devices havingcomputer readable program code stored therein, said program codeexecutable by one or more processors to implement a method, said methodcomprising: sending, by a first computer device to a second computerdevice via a broadcast or multicast communication, an event notificationof a notifiable management event, wherein the first computer device mayconnect to a management network via only a first network switch, whereinthe first computer device is unable to notify a management device of thenotifiable management event via the management network because the firstcomputer device is unable to connect to the management network via thefirst network switch, wherein the first computer device and the secondcomputer device are physically separated by an aisle; receiving, by thefirst computer device from the second computer device via a firstunicast communication, an acknowledgment of the event notification,wherein the second computer device is able to connect to the managementnetwork via the second network switch, wherein the broadcast ormulticast communication and the first unicast communication each use ashirt-range wireless communications technology comprising visible lightcommunication or data-over-audio communication.
 17. The computer programproduct of claim 16, said method further comprising: receiving, by thefirst computer device from the second computer device via a secondunicast communication, data communications that include a managementrequest from the management device on the management network;processing, by the first computer device, the management request toprovide a management response, and sending, by the first computer deviceto the second computer device via a third unicast communication, themanagement response for forwarding, by the second computer device, themanagement response to the management device over the managementnetwork, wherein the second unicast communications and the third unicastcommunication use the short-range wireless communications technology.18. The computer program product of claim 16, said method furthercomprising: receiving, by the second computer device from the firstcomputer device via the broadcast or multicast communication, the eventnotification of the notifiable management event; determining, by thesecond computer device, that the second computer device should handlethe event notification, and in response to said determining that thesecond computer device should handle the event notification, sending, bythe second computer device to the first computer device via the firstuni cast communication, the acknowledgment of the event notification.19. The computer program product of claim 18, wherein, prior to saidsending the acknowledgment of the event notification, the method furthercomprises: sending, by the second computer device to the managementdevice over the management network, the event notification; andreceiving, by the second computer device from the management device overthe management network, the acknowledgment of the event notification.20. The computer program product of claim 18, said method furthercomprising: receiving, by the second computer device from the managementdevice over the management network, a management message including arequest to establish a tunnel-through bidirectional link with the firstcomputer device for management data communications; in response to saidreceiving the management request, the second computer device setting upa bidirectional unicast communication the first computer device, whereinthe bidirectional unicast communication uses the short-range wirelesscommunications technology.